[SCSI] bfa: Serialize the IOC hw semaphore unlock logic.

Made changes to ensure only the function that comes first will execute
the IOC hw semaphore unlock logic.
Used IOC init sem register to serialize execution of the unlock logic.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>